Rubber modified phenolic friction particles, process for their preparation and friction elements containing them

(19)

(11)

EP 0 038 688 A3

(12)	EUROPEAN PATENT APPLICATION

(88)	Date of publication A3:
	10.03.1982 Bulletin 1982/10

(43)	Date of publication A2:
	28.10.1981 Bulletin 1981/43

(21)	Application number: 81301696

(22)	Date of filing: 16.04.1981

(84)	Designated Contracting States:
	BE DE FR GB

(30)

Priority:

17.04.1980 US 141140

(71)	Applicant: UNION CARBIDE CORPORATION
	()

(72)	Inventors:
	Pacala, Luba Anne () Blickensderfer, John Raymond ()

(54)	Rubber modified phenolic friction particles, process for their preparation and friction elements containing them

(57) Asubstantially completely cured particulate resin characterised by comprising:

(I) a mixture of phenols said mixture comprised of from 25 to 100 mole percent of tri- and/or tetrafunctional phenols and from 0 to 75 percent of difunctional phenols;

(II) from 1.1 to 3 moles per mole of phenol moiety of an aldehyde containing from 1 to 11 carbon atoms;

(III) from 0 to 1 mole per mole of phenol moiety of a primary, secondary or tertiary amine having up to 10 carbon atoms as a reaction promoting compound;

(IV) from 0.05 to 6 weight percent, based on the weight of components (I), (II), (III) and (V) of a protective colloid; and

(V) from 1 to 40 weight percent, based on the weight of component (I) of a rubber which is capable of forming a latex wherein the latex is compatible with components (I)-(IV); a friction element containing about 1 to 25 weight percent of such a resin; and a process for the production of substantially completely cured resin particles characterised by comprising the steps of:

(A) reacting, in an aqueous medium, at from about 50°C to about 100°C, (1) a mixture of phenols, said mixture comprised of from 25 to 100 mole percent of tri- and_/ortetrafunc- tional phenols and from 0 to 75 mole percent of difunctional pheriols. (II) from 1.1 to 3 moles per mole of phenol moiety of an aldehyde containing from 1 to 11 carbon atoms, (III) from 0.01 to 1 mole per mole of phenol moiety of an alkali metal or alkaline earth metal hydroxide or oxide or a primary, secondary or tertiary amine having up to 10 carbon atoms as a reaction promoting compound, (IV) from 0.05 to 6 weight percent of a protective colloid based on the weight of components (I), (II), (III) and (V), from 1 to40 weight percent, based on the weight of component (I) of a rubber which is capable of forming a latex wherein the latex is compatible with component (I)-(IV); for a period of time such that a particulate, heat reactive, and substantially water-insoluble phenolic resin is formed which is dispersed in said aqueous medium;

(B) adding an acidic compound to the aqueous dispersion of step (A) in an amount such that the pH of the aqueous dispersion is from 0 to 4; and

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